Mitutoyo—The go-to for machinists and engineers. Every part is made within a Mitutoyo automated factory and tested in-house in Japan. The spindle glides as you turn the thimble with a weighty, silky-smooth feel.

Dual Spindle—Best for quick quality checks. Set one spindle at your minimum tolerance and the other at your maximum. If your part slides past the maximum but not the minimum, it's good to go.